Fix some warnings under +w1 HP-UX compile

This is the world's fussiest compiler with +w1

Warnings reported by Richard Lloyd.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/movepick.h

@@ -61,11 +61,11 @@ private:
 
   const Position& pos;
   const History& H;
+  Bitboard pinned;
   MoveStack ttMoves[2], killers[2];
   int badCaptureThreshold, phase;
   const uint8_t* phasePtr;
   MoveStack *curMove, *lastMove, *lastGoodNonCapture, *lastBadCapture;
-  Bitboard pinned;
   MoveStack moves[256], badCaptures[64];
 };